Process for producing a textile fabric having the two sides thereof in differing colors



Patented July 12, 1949 PATENT QFFICE.

PRQCESSTFOR. PRODUCING A TEXTILE FAB- RIC HAVING" THE TWO. SIDES THEREOF-IN.

DIFFERING COLORS N Drawing. Application Septemberlt, 1944, Se-

rialwNo. 554,149; In Great Britain September 4 Claims.

1 5, ThislIIVEIHSiORT. relates to ther production of coloured textile fabrics.

. Weehave found that valuable textile fabrics can be obtained byapplying, aasaponifyi-ng; agent tc=a textile fabric consisting of or containing cellulose acetate or: other. cellulose ester fibres and causing saponification to take place, the conditions being suclrthatsaponification of the cellulose ester fibresw-isrefi'ected .to asubstantial degree on one side of the fabric while the cellulose esterfibreson" the-*otherside of the fabric-wemainunsaponified -or aresaponified to" a considerably less degree. Such fabrics arevery useful sinceby dyeing suitable dyes they can readily becolouredso that th'e shade of one side differs from that of the other For example, by dyeing'a fabric saponifled in this way with both a direct I cottom dye:- and a cellulose ester dye it is-possible to colourthe twosidesof the fabric in entirely diflleIlt ShadESi- Moreover; these valuable effects-can be obtained upon. fabrics of simple constructiomand'iwithout theinecessity for weavingan fabric: from twol different kinds of fibres and f arrangingthat; fibres: of. one: kind predominate-"on one. sideeof ithe fabric. and fibres of the other kindspredomiiiate." upon: the; other side ofthefabrim Thus..the.efliects.can.be obtained on. fabrics. comprisingrcellulose ester fibre yarns which appearon bothsides of the fabric.

In the saponified fabrics individual yarns have portionsvisible onone side of the. fabric which are saponifi'ed and'portions visible on the other side which are unsaponifieda Most conveniently tl'ie' saponifying agent is applied to onesideotthe -fabric in' the form of a preparation so: thickened that it does not penetratei 1 through torcthe: oppositeeside; of 1 the: fabric to any substantialeextentz. As'sthickening: agents, various wateresolublelgumssacarrsbe employed, for example gumtragacanth; Such water-soluble thickening agents may be supplemented. or replaced by water-insoluble inorganic thickeners, f or example-r French. chalk, fullersi earth, kaolin or like material of an absorbent character. These specificv materials. consist substantially of metal silicates.

It is very advantageous first to. apply to the side of the-materiallwhichv has to: remain substantially unsaponified. a mechanical or chemical resist which prevents-unwanted saponification on the side to which itv islappliedu. For: thispurpose water-soluble. gums, suchcas gumlgatto, can be employed. Again, insolublerwaterrepellent sub stances, for example: fats-or: waxes; can be: used. Further, the resistmay 'comprisean acid; e. g.

2: a solid water-insoluble acid; andparticularly a higher fatty" acid,; for instance" stearic acid or palmitic' acid or other fatty; acid, containing at least 1'2 carbon atoms. These water-insoluble acids may, if desired; be-used in conjunction with a" water-repellent wax, for example paraffin wax.

We have furtherfound that in the case of acid resists it is not essential to-restrict the application of the acid to one-side of the cellulose ester fabric. Extremely goodresu-lts can be obtained, fer instance, by applying" a'thickened saponifying medium to one side only of a fabric which has been uniformly-impregnated with an acid substance. Though the acid substance is neutralised by the saponifying agenton'the sideof the material to which the latter isapplied, it nevertheless servesto l'ocalise the action of the saponifying agentandto reduce substantially or prevent saponifi'cation of the fibreson the opposite side of the material: Higher fatty acids are very suitable for use-as resists in this manner. They may, for instance; be *appliedto the-material in the form: of'solutions. in volatile organic liquids, e. g. volatile Y chlorinated hydrocarbons, and the. volatile: liquid: removed by evaporation. Again. they may: be .appliedxto the. material in the form of aqueous solutions. of their ammonium. salts and thematerial; then heated so; as to decompose therammonium salt; drive off the ammonia and leaverth'eaqfatty acid on the material. This. latter is a. particularly convenient Way of utilising the highersfatty acidssnch as stearic or. palmitic acid.

The saponifying. agents. or the resists or both may be applied to the fabric either locally or over the whole surface of thefabric. Again the saponification maybe to different degrees as between different saponifiedportions of the fabric with corresponding differencesin dye afiinity. Thus the saponifying agenttmay. beapplied over the whole surface ofthe fabric. and, local removal of saponifying1 agenteffected, forexample by bring.- ing the moist. material into contactv with a surface engravedin a.-pattern. Inthis way, for in stance, fabrics can beobtained which, on dyeing with. a suitable dye or mixture. of dyes yield on the sapcnified side. effects resembling. the well known batik effects.

As saponifying agents, the alkali metal hydroxides and carbonates are especially useful. They can be applied to the material'in the form of aqueoussolutions, thickened for instance in the manner described above, and the desired saponification of oneside'of the fabric effected or completed by drying: the material, for example in hot air or on steam-heated cans. After application of the aqueous saponifying agent to the material, the latter may be allowed to remain in the moist state for a short time, for example 1-5 minutes, before drying. By suitably pro longing the period during which the material is allowed to remain in the moist state the required saponification can usually be obtained without drying the material; avoidance of drying has the advantage that the thickening agent is more readily Washed from the material. After saponification has been effected any residual saponifying agent should be neutralis'ed, for example by treatment with dilute hydrochloric acid or other aqueous acid. The fabric is then washed to free it from products of the saponification reaction and from the thickening agents and resists employed. The degree of saponification of individual filaments should be such as to impart affinity for direct cotton dyes.

The two sides of fabric saponified in the above manner can be dyed in a wide range of contrasting shades by dyeing the fabric on the one hand with a dye which has afiinity for the cellulose ester but little or no affinity for cellulose and on the other hand with a dye which has affinity for cellulose but little or no afiinity for unsaponified cellulose ester. The saponified material takes up the dye having affinity for cellulose. It may also take up the cellulose ester dye to a greater or less degree, depending on the extent to which the filaments have been saponified. The dye used for colouring the unsaponified cellulose ester is advantageously of the water-insoluble type applied in the form of an aqueous dispersion. The two types of dye may be applied to the material in separate operations or they may be applied in a single bath when compatible one with the other. Printing and other methods of applying dyes locally to the material may be employed if desired. Again, dischargeable colouring matters can be employed either for the saponified material or for the unsaponified material or both and the coloured materials subjected to a discharge printing operation. A very wide range of differentially coloured and patterned materials can thus be obtained.

If desired dyes or dye components capable of being fixed on the saponified portion of the material can be applied in conjunction with the saponifying agent thus effecting simultaneous saponification and colouring. Thus vat dyes in leuco form or as sulphuric esters of the leuco compounds, e. g. Soledon Jade Green XS or Indigosol O, can be included and subsequently converted to the parent vat dyes on the saponified portions of the material. Again enolic coupling components having affinity for cellulose, for example arylamides of 2:3-hydroxynaphthoic 7 acid or other ortho-hydroxy-carboxylic acid, or

arylamides of aceto-acetic acid or other betaketo-carboxylic acid, can be included and subsequently developed to azo dyes on the material with diazo compounds; if desired diazo compounds in stabilised form can be used and applied together with the enolic coupling component.

The invention is illustrated by the following examples:

Example I A cellulose acetate fabric of twill weave is secured, dried, and padded in an aqueous solution prepared with 50 to 75 grams per litre of stearic acid and sufllcient ammonia to dissolve the latter. The padding is conducted so that the material retains about 75% of the aqueous solution based on the weight of the fabric. The material is then dried. Alternatively the stearic acid can be applied as a to grams per litre solution in perchlorethylene and the material then dried. The material is then back-filled with a paste of the following composition:

200 grams 6% gum tragacanth, 20 grams caustic soda in 50 cos. water, 35 grams French chalk.

The fabric is then allowed to hang in the air for 1-5 minutes, dried and the remaining alkali quickly neutralised by treatment with dilute hydrochloric acid. Finally, the fabric is thoroughly washed and then dyed in a single bath containing both a direct cotton dye and a water-insoluble dye having direct affinity for cellulose acetate.

The dyeing can be accomplished for instance on the jigger in a bath containing 2 grams per litre of soap at C. using the following mixture of dyes:

Per cent 2:4 dinitro-4-amino-diphenylamine (10% paste) 0.45

1 amino 4 hydroxy anthraquinone (10 paste) 0.30

Durazol Fast Yellow B 400 powder (I. C. I.) 0.5 Durazol Fast Blue 4 G. 200 powder (I. C. I.) 1.0

The percentages of the dyes are based on the weight of the material. Again it can be accomplished at 80 C. in a :1 bath containing 1 gram per litre of sodium lauryl sulphate and 12 grams per litre of common salt using the following mixture of dyes:

Per cent 2:4 dinitro-4'-amino-diphenylamine (10% paste) 1.8 1 amino 4. hydroxyanthraquinone (10% paste) 1.50 1 methylamino 4 (beta hydroxyethylamino) -anthraquinone (10% paste) 0.1 Durazol Fast Yellow B 400 powder (I. C. I.) 3.0 Chlorazol Brown MS (I. C. I.) 0.5 Chlorantine Fast Blue GLL 20o powder C. A. C.) 0.1

The percentages of the dyes are based on the weight of the material. The side to which the saponifying agent has been applied is coloured a chocolate shade and the other side a yellowish brown shade.

Example II A fabric of the kind referred to in Example I is scoured and dried and the face is filled with an aqueous solution of gum gatto containing 30 grams of gum per litre. The material is then dried and is then back-filled with the alkaline saponifying paste referred to in Example I. Subsequent treatment of the fabric is also effected as in Example I.

Having described our invention, what we desire to secure by Letters Patent is:

1. In a process for the production of a textile fabric having the two sides thereof colored in different colors by a dyeing process, the steps which comprise substantially completely impregnating a textile fabric comprising fibers of an organic acid ester of cellulose with a solid waterinsoluble fatty acid containing at least 12 carbon atoms, applying to the one side of the fabric a solution of a saponifying agent so thickened that it fails to penetrate through to the opposite side,

permitting the saponifying agent to saponify the organic acid ester of cellulose fibers on the side to which it is applied and thereafter dyeing the fabric with a dye having an affinity for the organic acid ester of cellulose fibers but not for the saponified fibers and with a dye having an aifinity for the saponified fibers but not for the organic acid ester of cellulose fibers.

2. In a process for the production of a textile fabric having the two sides thereof colored in different colors by adyein process, the steps which comprise substantially completely impregnating a textile fabric comprising fibers of cellulose acetate with a solid water-insoluble fatty acid containing at least 12 carbon atoms, applying to the one side of the fabric a solution of a saponifying agent so thickened that it fails to penetrate through to the opposite side, permitting the saponifying agent to saponify the cellulose acetate fibers on the side to which it is supplied and thereafter dyeing the fabric with a dye having an afllnity for the cellulose acetate fibers but not for the saponified fibers and with a dye having an affinity for the saponified fibers but not for the cellulose acetate fibers.

3. In a process for the production of a textile fabric having the two sides thereof colored in different colors by a dyeing process, the steps which comprise substantially completely impregnating a textile fabric comprising fibers of cellulose acetate with stearic acid, applying to the one side of the fabric a solution of a saponifying agent so thickened that it fails to penetrate through to the opposite side, permitting the saponifying agent to saponify the cellulose acetate fibers on the side to which it is applied and thereafter dyeing the fabric with a dye having an afimity for the cellulose acetate fibers but not for the saponified fibers and with a dye having an aflinity for the saponified fibers but not for the cellulose acetate fibers.

4. In a process for the production of a textile fabric having the two sides thereof colored in different colors by a dyeing process, the steps which comprise substantially completely impregnating a textile fabric comprising fibers of cellulos acetate with palmitic acid, applying to the one side of the fabric a solution of a saponifying agent so thickened that it fails to penetrate through to the opposite side, permitting the saponifying agent to saponif the cellulose acetate fibers on the side to which it is applied and thereafter dyeing the fabric with a dye having an ailinity for the cellulose acetate fibers but not for the saponified fibers and with a dye having an affinity for the saponified fibers but not for the cellulose acetate fibers.

ALBERT MELLOR. RALPH JAMES MANN.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 646,379 Tagliani Mar. 27, 1900 1,266,955 Knifller May 21, 1918 2,020,698 Platt Nov. 12, 1935 2,068,770 Schwarzchild Jan. 26, 1937 2,145,364 Monc-riefi Jan. 31, 1939 2,248,048 Allan July 8, 1941 FOREIGN PATENTS Number Country Date 346,544 Great Britain Apr. 16, 1931 Certificate of Correction Patent N 0. 2,475,672 July 12, 1949 ALBERT MELLOR ET AL.

It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 3, lines 71 and 72, Example I, for the Word secured read scoured;

column 4, line 26, for (10 read (10%; column 5, lines 19 and 20, for "supplied read applied;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 10th day of January, A. D. 1950.

THOMAS F. MURPHY,

Assistant Oommissz'oner of Patents. 

